/p*-nam'bik/ (From the scene in the film, "The Wizard of Oz" in which the true nature of the wizard is first discovered: "Pay no attention to the man behind the curtain"). A term coined by Daniel Klein
The ultimate pnambic product was "Dan Bricklin's Demo", a program which supported flashy user-interface design prototyping.
There is a related maxim among hackers: "Any sufficiently advanced technology is indistinguishable from a rigged demo." See magic for illumination of this point.
["Open Channel", IEEE "Computer", November 1981].